Apex domains cannot have CNAME records.
Question and response
Question
dig telecu.net. NS
Answer
telecu.net. 4 NS ns2.telecu.net.
telecu.net. 4 NS ns4.telecu.net.
telecu.net. 4 NS ns1.telecu.net.
telecu.net. 4 NS ns3.telecu.net.
Authority
The response has no authority records.
Additional
ns1.telecu.net. 4 A 181.233.48.2
ns2.telecu.net. 4 A 200.6.14.2
ns3.telecu.net. 4 A 66.231.64.4
ns4.telecu.net. 4 A 51.81.52.225
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0